Thermal management in e-motorhomes: The future is here

The wave of electromobility is now spilling over into the travel and motorhome sector. Against this backdrop, Webasto’s innovative e-thermal management concept represents a crucial solution for range and comfort in electric motorhomes.

Electrification is slowly but powerfully rolling towards the camping and mobility industry. While the age of electromobility has already dawned in cars, the transformation in the travel and motorhome sector is still in its infancy. However, the desire for sustainable travel is driving technological change here too. The industry is challenged by specific requirements for range and weight, as well as the complexity of vehicle technology.

While many manufacturers currently focus primarily on drive concepts, Webasto addressed an equally important component at the Caravan Salon with an innovative e-thermal management concept: the uncompromising comfort of travelers. After all, the energy demand of e-motorhomes, due to the additional energy required for heating and air conditioning, is about twice as high as that of cars. “Especially at low temperatures, this massively affects the range. The weight of the necessary batteries and electric drives also puts a strain on the overall weight restrictions of the vehicles,” explains Dr. Leopold Gurtner, Director Global RD at Webasto.

To meet these challenges and maximize both comfort and efficiency of electric motorhomes, intelligent thermal management systems are moving into focus. These are intended not only to warm or cool the interior, but also to optimize the performance and longevity of vehicle components. So how to balance comfort, range, and weight? At this year’s Caravan Salon, Webasto introduced a forward-looking fully integrated thermal management concept that uses available components and reduces space, weight, and maintenance costs.

The path to an integrated overall concept

In the concept, Webasto’s thermal management experts outline a holistic thermal management system that efficiently generates heat or cold for travel, stay, and sleep. For maximum range, it keeps the drive battery in its optimal temperature range. An integrated heat exchanger absorbs heat from the surroundings and dissipates excess heat. The WP80 heat pump generates heat and cold with high efficiency for distribution in the vehicle. The HVAC system in turn distributes cooled or warm air in the driving area, thereby also defogging the windshield. For rapid heating, the Webasto high-voltage heater is used, while floor heating and radiators take care of heat distribution.

Also part of this system is the SP80 Hydro air conditioner, only eight centimeters high, which delivers warm or cold air as needed, saving weight as the outdoor unit is not needed. Solar cells supplement the system by providing additional energy and contributing to the vehicle’s autonomy. The refrigerator is cooled by the heat pump, while a boiler supplies the shower and hand washing water. The comprehensive control of the system is done via the Cronus integration platform, which allows for individual settings and provides an interface to the vehicle. All functions, including temperature and air flow distribution, can be controlled and monitored via a display or the ThermoConnect app.

The future is very close

The concept is much more than a futuristic study with many unknowns. “Like in a concert, we have gathered the orchestra members who can play best together. It sounds good when everyone can practice together.” The art lies in meeting the demands of the ensemble. “The battery likes about the same climatic conditions as humans, it feels comfortable at temperatures between 15 and 35 degrees Celsius. But there are also units and parts in the vehicle that need other conditions,” says Gurtner. This makes the coordination complex and technically complicated. Depending on the “use cases”, the requirements for electric thermal management also shift. Gurtner: “When charging, we have a completely different energy ratio in the vehicle than when driving or when the vehicle is just standing. For example, when charging, heat energy is created in the battery, the battery needs to be cooled.”

Non-physicists may now be asking where the energy for cooling comes from and where the battery’s heat goes. For the experts at Webasto, a door opens into a huge room full of mathematical formulas: “Our calculations include factors such as the size of the battery, power, current and future charging technologies, temperatures, and also the amount of energy available. The rule always applies: Energy is a precious commodity. So we always ask ourselves what we can do with the energy just generated,” Gurtner explains.

Ultimately, the art of electric thermal management lies in controlling, intelligently redirecting, and reusing the energy flows in the vehicle. Gurtner provides an example: “When the battery is charged, heat is generated, which could be used to heat the cabin. Conversely, I can store the energy of a too hot cabin in the battery and use it in the evening to heat the cabin.”

From Concept to Implementation

Webasto is already very advanced with the electric thermal management concept. Gurtner expects that test systems as a kind of “proof of concept” will be set up this year. The thermal management team is already working with industry partners from other sectors, such as city buses, that are somewhat more advanced in electrification on e-thermal management systems.

Gurtner estimates that the motorhome industry is now increasingly moving into electrification and that the first vehicles will be visible on the market in 2025 and production vehicles will be available a year later. By then, many of the challenges of electrification will still have to be mastered, but thermal management will have long since been under control.